A 45-year-old construction worker is brought to the emergency department after collapsing at a job site on a hot summer day. His vital signs are: temperature 104.2°F (40.1°C), pulse 120 bpm, respirations 28/min, and blood pressure 90/60 mmHg. The patient is conscious but appears confused and has hot, dry skin. A nurse is caring for this patient with hyperthermia. Which nursing intervention should be implemented first to reduce the patient's body temperature?

Immediate external cooling (removing clothing and applying cool cloths) is the priority to rapidly reduce core temperature in hyperthermia. Other options are less effective or inappropriate for initial management.

Clinical Context and Priority Setting
This patient presents with classic signs of heat stroke, a medical emergency defined by a core temperature above 104°F (40°C) and central nervous system dysfunction (confusion). The critical pathophysiological concern is the failure of the body's thermoregulatory mechanisms, leading to hyperthermia—a state distinct from fever. In fever, the hypothalamic set point is elevated by pyrogens; in heat stroke, the set point is normal, but the body's ability to dissipate heat is overwhelmed. This distinction is the foundation for prioritizing nursing interventions.

Why Antipyretics Are Contraindicated
Administering acetaminophen (option 2) is ineffective and potentially harmful in this scenario. Antipyretics work by inhibiting cyclooxygenase in the central nervous system, which lowers an elevated hypothalamic temperature set point back to normal. Since the patient’s hyperthermia is not caused by a pyrogen-driven shift in the set point but by environmental heat gain and failed dissipation, antipyretics will not reduce the temperature. Furthermore, in a patient with heat stroke, there is a risk of hepatic injury, and administering acetaminophen could compound hepatotoxicity.

Rationale for Immediate External Cooling
The correct first intervention is to remove excess clothing and apply cool, wet cloths to the skin (option 1). This initiates evaporative cooling and conduction, the two primary mechanisms for rapid heat dissipation in the absence of a functional thermoregulatory response. The patient’s hot, dry skin indicates that the body’s primary cooling mechanism—evaporative heat loss through sweating—has failed. Applying cool water to the skin and maximizing air exposure artificially restores this process. The goal is to reduce the core temperature as quickly as possible to prevent irreversible neurological and cellular damage. The cited guidelines on clinical management emphasize that in hyperthermic emergencies, physical cooling measures are the cornerstone of immediate treatment, as pharmacological interventions are not directed at the underlying mechanism of heat accumulation.

Analysis of Other Options
Encouraging oral fluid intake (option 3) is contraindicated in a patient with an altered level of consciousness due to the high risk of aspiration. While fluid resuscitation is critical for the hypotensive state (blood pressure 90/60 mmHg) caused by dehydration and peripheral vasodilation, it must be achieved through intravenous access, not oral administration. Placing the patient in a warm blanket to prevent shivering (option 4) is counterproductive. Shivering is a thermogenic response that can occur during aggressive cooling, but the immediate priority is to lower the dangerously high core temperature. If shivering occurs, it is managed with benzodiazepines per protocol, not by halting the cooling process. The primary objective remains rapid temperature reduction through external cooling measures.